Beers are categorized into styles such as Stouts, Porters, Weizen, Pilsner, and India Pale Ale. Most beer styles originated in a particular country, region or city. There are literally hundreds of unique styles of beer from around the world. Arguably the best accepted style guide for the homebrewer today is the BJCP Style Guideline which currently contains 28 main style categories and is used to judge most US beer competitions.